Two-piece buckles that snap together and latch automatically upon adequately inserting a male component into a female component are known and used in a variety of applications. A piece of webbing or strap can be attached to each of the components, and one or both buckle components can be adjustably retained on the strap or webbing. It is also known to have both components in fixed locations relative to a strap or web that is sewn or otherwise fixedly secured to the buckle component. Such buckles are known and used for a variety of applications, including outdoor recreational products like backpacks, bike helmets and life vests and other equipment. Two-part buckles are used also on luggage, bags, clothing and the like.
In one known design for buckles of this type, the female component defines a pocket and includes openings or windows on the lateral, opposed sides of the pocket. The male component includes arms having outward protrusions slightly wider than the width of the female component at some positions from the entrance to the window. As the male component is inserted into the female component, the arms are deflected inwardly and thereafter are allowed to rebound outwardly when the protrusions align with the windows in the female component. With the protrusion extending slightly outwardly at the window, the male component is secured within the female component. For added security, additional confronting surfaces on the male and female components engage one against another as the male component reaches a final, locked position. The strength of the buckle to resist unintended release when pulling force is applied against either component is determined by the nature of the engagement between the male and female component. The resistance to intended release, or stated another way, the difficulty in unlatching the buckle, is determined by the deflectability of the arms upon squeezing the protrusions inwardly from the window, and the resistance of the engaging surfaces to slide past or otherwise disengage from each other.
While buckles of the type described have had success in many applications, they are not without deficiencies, and improvements are sought after and advantageous. For example, to improve resistance to unintended release of the buckle when the buckle is placed under load; bulky, thick components have been used. Some buckles are difficult to release when under load. While such buckles may release easily when not under load, if the engaging surfaces are directed angularly forward, release requires movement of the male lock arms such that the male member is actually driven deeper into the female component as engaging surfaces slide beyond each other. When under load, this causes an increase in the load, and as a result, the release mechanism can be difficult to operate. Further, in manufacturing buckles of the type described, large tolerances are needed to overcome lock surface angles in the direction of latching. Accordingly, when latched but not under load, the male and female components may feel loosely fit one in the other and may even rattle or otherwise move one with respect to the other. While such looseness may not affect overall performance of the buckle, the user may feel that the buckle is not secure. The user may adjust the adjustable strap to make the strap exceedingly taut so that rattle is eliminated in that the buckle is under continuous load. This, then, can result in the aforementioned difficulty in releasing the buckle under load.